1. Field
A process for operating a measurement device of the vibration type is disclosed.
2. Background Information
A measurement device of the vibration type is also known as a Coriolis measurement device in which a measurement tube through which the measurement medium flows is excited to vibrations. With a measurement device of the vibration type, the flow rate of a fluid medium flowing through a measurement tube can be measured. Other parameters of the medium, such as for example the viscosity or the density of the medium, can also be measured, either to supplement the flow rate or alone.
Vibration generators are used in the indicated measurement device of the vibration type. These vibration generators are based on an accurate measurement of at least one natural frequency of the vibration system.
In this connection mechanical transducers are used. This system is known from EP 1496341 A2, the contents of which are incorporated herein by reference in their entirety.
When used in a measurement device of the vibration type, the vibrating system relates to pipelines through which the medium to be measured flows. In this way the natural vibration of the vibrating system changes of course, and is thus dependent on the flow rate and the density of the liquid. But here it also holds that the amplitude of the measured vibration signal is maximum when the vibration system is excited to its natural frequency.
In a known measurement device of the vibration type, the measured vibration signal is amplified and fed back to the exciter arrangement. The measured vibration signal can be noisy in this connection so that frequency instabilities and other unwanted nonlinear effects can occur.